Generally, in a typical casting process, one or more masters are provided at least partially in the form of a part to be cast. The master is then heated and pressed into a half of a sand mold to form the first half of the part to be cast. The sand mold includes material which makes the sand adhere to itself when it is heated. Accordingly, the hot master is pressed into the sand and pulled away, and leaves an impression in the sand in the shape of the first half of the part to be cast. The other half of the sand mold is also pressed to form the second half of the part. The two halves of the sand mold are then placed together and molten material is poured into the cavity of the sand mold. The molten material is then formed in the shape of the master.
It is known in the casting industry that castings after production are subjected to several handling operations until they reach subsequent work stations, at which further operations will be performed upon the cast part. During these handling operations, confusion can arise between cast parts, resulting in serious mistakes and severe damage during subsequent operations. It is generally difficult to distinguish cast parts of different compositions originating from different batches by their external appearance. Accordingly, attempts have been made to develop identification means for marking cast parts for future identification.
The most common presently used system for identifying cast parts comprises the use of a metal identification tag removably secured to the master. Generally, a slot is drilled in the master and a pair of holes are drilled and tapped at the bottom of the slot. A metal identification tag is then placed into the slot and screws are inserted through the tag and into the tapped holes, and are tightened to secure the tag within the slot. This system is very problematic for a number of reasons. The biggest problem with this prior art system stems from the fact that sand from the sand mold has a tendency to work its way into the tapped holes in the slot of the master. When these tags are changed during a production operation, the screws are removed, and the tag is replaced with a different tag, and the screws are replaced. If there is sand within the tapped holes as the screw is replaced, it is very easy to strip the threads of the tapped holes. This stripping of threads causes serious manufacturing problems because the holes must be welded closed, redrilled and retapped, which is a very time consuming and expensive operation and will cause significant down time for a manufacturer. Significantly, many masters are formed to comprise twenty or more part shapes, each shape having a tag thereon. Accordingly, if one tapped thread is stripped on a large master including a large number of shapes, production is seriously hindered as the hole is welded, redrilled, and retapped because the entire master is out of use as the one hole is repaired.
In order to avoid the above-referenced problems experienced with prior art systems, it would be desirable to develop an identification system for ingots which is quickly and easily replaced, and does not require screws and tapped holes to secure the identification tag.